Fear is one of the most common things that holds us back from doing what God calls us to do. We fear making wrong decisions, and we fear what other people think of us on a daily basis. No matter what your fear may be, if left unchecked, it will prevent you from living to the fullest.
In this verse, the God of Israel challenges His people to be strong and courageous, to not fear their enemy, for He is with them. No matter how frightening their circumstances were or how powerful their enemies appeared, they were not to be afraid but to trust in the Lord with all their hearts. Moses assured them that the Lord would always be with them, leading and comforting, supporting and helping them wherever they went. 
It is the same God who provides us with His Holy Spirit to lead and guide, to support and assist us. Just as He challenged Israel, the Lord challenges us to be strong and courageous in His mighty strength. There is nothing we need to worry about because He is always with us regardless of the circumstances. What could be a greater reassurance of faith than that provided by the Lord? What could be more comforting than the Lord's promise that He will never fail us or forsake us? 
As we continue our journey through life, we'll encounter even more challenges and difficulties. Yet the Lord will strengthen us, and His mighty power will make us strong. Let the Lord lead you, and be strong and courageous!

Dear Heavenly Father, I know You are always with me, and I have nothing to fear. When I feel weak, You are strong; when I feel abandoned, You give me love. You are always available to lead me, comfort me, help me, and love me whenever I need you. I pray for strength to fight the demons and endure the difficulties, Lord. Please help me to be courageous no matter what challenges I face today and to always lean on You. 
In Jesus's name I pray. Amen.